This invention relates generally to prosthetic devices and methods and more particularly to penile implants.
In order to remedy the effects of certain types of functional impotency, implants have been developed for surgical insertion in a penis to simulate a natural erection.
One of the first surgical implant techniques entailed the implanting of a solid, semi-rigid rod in each corpora cavernosa of the penis. While such a technique does result in the prevention of the penis from collapsing, thus permitting penetration during coitus, the technique suffers from various drawbacks. The most serious drawback of the semi rigid rod implant is that inasmuch as the rods as narrow, semi-rigid members, they do not increase the diameter or the length of the penis nor do they make the penis hard. Moreover, the solid rods are uncontrollable so that once surgically implanted, the penis is permanently extended.
In order to overcome the disadvantages of the solid rod technique a penile implant was developed utilizing a flexible elastic tube and a compressable container containing a fluid to be transferred from the container into the tube when the container is compressed so the fluid displaced into the tube elongates the tube and renders it relatively rigid. The tube is surgically implanted longitudinally along the penile shaft while the container is implanted in either the scrotum or in the abdominal cavity. An example of such a device is shown in U.S. Pat. No. 3,853,122 (Strauch, et al). While the Strauch, et al device appears to provide more functionality than the semi-rigid rods (since the Strauch device allows controlled actuation), the Strauch device does not appear capable of rendering the penis hard and enlarged.
Another implant device for effecting an erection is disclosed in U.S. Pat. No. 3,954,102 (Buuck). The Buuck prosthesis comprises a pair of expandable, resilient silicone rubber cylinders which are implanted in the corpora cavernosa to replace their function. A closed fluid supply is also implanted in the body and connected, via tubing, to the cylinders to inflate the cylinders and cause them to stretch, whereupon the diameter and length of the penis is increased. The fluid supply is in the form of an elastomeric bulb, which is squeezed through the person's skin to operate the device. Various valves are provided in the system so that the degree of the erection of the penis is controlled by varying the amount of fluid provided to the cylinders upon the squeezing of the bulb. Deflation of the cylinders is accomplished by actuating a bypass valve.
The implant disclosed in the Buuck patent appears to overcome various disadvantages of prior art techniques inasmuch as it not only prevents a penis from collapsing, but also enables the penis to become hard and enlarged upon actuation. However, inasmuch as the resilient cylinders are pressurized and expanded during the erection cycle of the device tensile stresses are produced in the material forming the cylinders. The repeated stresses of actual operation result in the eventual rupture of the cylinders, thus requiring surgical replacement.
Other expandable cylinder-type penile implants have been disclosed in the patent literature, such as disclosed in U.S. Pat. No. 4,009,711 (Uson). The Uson device, like other resilient, expandable cylinder implant devices has the tendency to fail or rupture due to the stresses engendered during repeated inflation and deflation.